Epic Games has released Unreal Engine 4.26, delivering a range of new improvements including the production-ready Hair and Fur that was recently featured in the Weta Digital Meerkat short film. It also delivers animation in the sequencer, sky and cloud environment lighting, better nDisplay support for Virtual Production (VP), a new water system, the remote control API often used in VP, and collaborative viewer template enhancements.
Above is a summary of the new features in 4.26
Play with Molly the Meerkat Yourself
As part of the 4.26 release, Epic is offering the entire scene as a free sample project download. Artists can get the fully rigged, groomed, and animated characters—together with their environment, cameras, effects, and audio, plus the Maya files, final textures and materials, and more.
Hair and Fur
Hair and Fur are production-ready in 4.26, delivering the ability to edit, simulate, and render strand-based hair, fur, and feathers. Hair and Fur now features a new Asset Groom Editor for setting up properties and compatibility with features such as DOF and Fog. LOD generation is built-in, and users are now able to generate cards and meshes for lower-end hardware in-engine as an experimental feature.
Weta Digital recently completed a UE4 short film that road-tested the creative opportunities of using these new Unreal Hair and Fur tools in a traditional narrative story. The film was created with a small talented group of Weta Artists, but not using Weta’s proprietary hair tools, it was created with a pipeline of standard tools: Autodesk Maya, Peregrine Labs’ Yeti, and UE4’s 4.26 new Hair and Fur.
The team used Live Link to aid in their animation while in Autodesk Maya and then they exported an Alembic Hair Groom to UE4 for the final composition, lighting, and rendering. Live Link provides a common interface for streaming and consuming animation data from the external sources DCC software, such as Maya, into UE4. Thelvin Cabezas, CG supervisor at Weta Digital comments that “having the live link is part of what made this project possible… We adjust our animation controls in Maya and see what it looks like in UE4 and this gives us a really controlled approach to the way we work”.
The meerkat film was always designed to test using Unreal for making a traditional short film rather than an interactive game. The Unreal Engine’s Control Rig and Animation features in Sequencer were used to create the final piece, and then the Movie Render Queue was used for export. This provided a remarkable finished piece. The meerkat, named Molly, was groomed with 400,000 strands, the Eagle ended up with over 3.7M stands (even more than Weta Digital reported). In the past, artists might have had to address a bird’s wings using cards in a game engine, but the new Hair and Fur simulation produced feature film level, fully accurate winged feathers.
The Weta Digital piece not only showcases the new Hair and Fur, but it shows what talented artists can do, and how far these new easily accessible but cutting-edge tools have now come. The piece works not due to a special build or custom code that only the R&D team at Weta could write. It comes from the talented and experienced Weta animators using tools anyone can now get their hands on.
Adding further believability to their characters’ movements, users can now create animations in Sequencer by blending animation clips such as motion-captured data; the workflow will be familiar to animators who’ve worked in other nonlinear animation editors. Animators can preview skeleton animations to easily see how one skeleton blends into the next, and match joint placement for a smooth transition between clips. The feature is integrated with Control Rig, which now offers an experimental full-body IK solution in addition to the standard FK/IK.
Immersive natural worlds and environments
Unreal Engine 4.26 introduces a new Volumetric Cloud component that is able to interact with Sky Atmosphere, Sky Light, and up to two directional lights, improving the quality of both realistic and stylized skies, clouds, and other atmospheric effects. The atmosphere can receive volumetric shadows from meshes and clouds; lighting and shadowing updates in real-time to reflect time-of-day changes. In addition, there’s a new Environment Lighting Mixer window that enables all components affecting atmosphere lighting to be authored in one place. This release also sees the introduction of a new water system, enabling artists to define oceans, lakes, rivers, and islands using splines. Users can adjust and visualize the depth, width, and velocity of rivers along their lengths, and the wavelength, amplitude, direction, and steepness of waves on oceans and lakes. The system includes a new Water Mesh Actor that uses a quadtree grid to render detailed surfaces up close, smoothly transitioning to simplified ones at distance. Built-in fluid simulation enables characters, vehicles, and weapons to interact with the water; the fluid also responds to Terrain, such as reflecting ripples off the shore and reacting to river flow maps.
Extended virtual production toolset
Unreal Engine 4.26 leverages technology such as NVIDIA’s NVLink, which enables data to be transferred between two GPUs at very high speed, in order to support the increasing number of pixels on today’s LED volumes. This allows any viewport to be rendered on another GPU. For example, one display-facing GPU would render the entire scene while another handles the inner frustum, passing the pixels back to the first one.
The 4.26 release also introduces a new fully REST-compliant Remote Control API that enables users to easily collect and organize any parameters or function libraries from the Unreal Engine UI into customizable presets. These can be used in a panel in the Unreal Editor, or seamlessly connected to widgets—such as radial dials, sliders, or color pickers—in web applications, without coding. For example, this could enable an artist on a virtual production stage to easily change the sky rotation or the sun position from an iPad. This feature also benefits broadcast and live events teams who may need to make changes remotely in real-time.
Enhanced high-quality media output
Movie Render Queue lets users create high-quality frames with accumulated anti-aliasing and motion blur for film and television, cinematics, and extremely high-resolution images for print. For example, in the Meerkat project, Weta Digital output the film at 1920×1080 but with all the settings turned up in quality in Movie Render Queue, and they also exported some test clips at 4K resolution.
4.26 adds new features to Movie Render Queue, now making it possible to output render passes including matte IDs, camera motion vectors, Z-depth, ambient occlusion, reflections, and more so that users can refine their images in downstream compositing such as Foundry Nuke, or photo-editing such as Adobe Photoshop. Movie Render Queue also now supports OpenColorIO (OCIO), enabling users to work in any color space while ensuring that their image will look as intended on its target platform. In addition, 4.26 delivers new support for exporting multi-channel EXRs, Apple ProRes and Avid DNxHR codecs, and Final Cut Pro XML EDLs, as well as the ability to integrate render farms.
More effective collaborative design reviews
There are now significant usability and performance improvements in the Collaborative Viewer template that enables multi-user design reviews on VR/AR/Desktop, both enhancing the collaborative design review process and allowing more users to join a session. In addition, there’s now support for voice communication between participants over VOIP using in-engine peer-to-peer protocols.
Unreal Engine 4.26 also offers a completely new Virtual Camera system, enhanced DMX support, and new Datasmith exporter plugins for Rhino and Naviworks, new improvements to the Chaos physics tool, ray tracing, and new GPU Lightmass.
Weta Digital used Lightmass for ambient occlusion, with the baked light for indirect in a lighting importance volume in the Meerkat short film. This was coupled with dynamic lighting, by keeping the direct light live in UE4 so the team could craft the quality of the light and produce soft bounce from the earth on the meerkat and beautifully backlight feathers on the Eagle.